SPACECRAFT COORDINATION CONTROL USING PID+ BACKSTEPPING

In this paper we present a PID+ solution to the problem of relative translational and rotational tracking, using the concept of integrator backstepping. By using an integrator augmentation technique, we include integral effect in the controller to account for the unknown orbital perturbations. The controller solution utilizes the quaternion representation to achieve a shorter rotation path on commanded attitude changes, and the equilibrium points in the closed-loop system are proved to be uniformly exponentially stable. Finally, simulation results are presented to show the controller performance.